Structure of air pump with low noise

ABSTRACT

In the structure of an air pump with low noise, the diameters of an inlet and an outlet in the main body of the pump are reduced (such as 1.3 mm) to be smaller than that normally used (such as 2.0 mm), and the areas of air control films used are coincidently reduced, the cross-sectional area of a noise-silencing channel is also set in coincidence with the areas of the inlet and the outlet. Thereby, sounds generated by repeated beating of the air control films on the inlet and the outlet against the inner walls of the main body of the air pump can be reduced; thus noise in operation of such an air pump can be reduced too.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention is related to a structure of an air pump with low noise, and especially to a structure more effective in lowering the noise generated in operation of an air pump.

[0003] 2. Description of the Prior Art

[0004] An aquarium, as an example, has to be continuously supplied with air for well making surviving of bred fishes. Generally, an air supplying device for an aquarium is a small air pump; mostly, such an air pump has a mandrel of a moor to eccentrically drive an elastic cap, by reciprocal movement of the elastic cap, air in the pump is subjected to pressure, and then is delivered into the aquarium via an air delivery pipe. Such an air pump has to continuously pump air, and thereby is subjected to generating noise; while the aquarium is normally placed in a room, such sustaining noise may affect working and rest of the persons indoors. In view of this, noise silencing becomes an important factor in designing.

[0005] By virtue that such an air pump makes noise, the air pumps now available mostly are provided each with a noise-silencing channel at the junction of it with the elastic cap. However generally, the length of a noise silencing channel can have is limited, thereby the effect of noise silencing thereof is not so ideal as expected.

SUMMARY OF THE INVENTION

[0006] The object of the present invention is to provide a structure of an air pump with low noise, an air inlet and an air outlet smaller than those normally used are provided in the main body of the pump and are provided each with a film with a reduced area, a noise-silencing channel thereof is provided and has a sectional area like that of each of the air inlet and the air outlet. Thereby, the noise made by beating of the individual films of the air inlet and the air outlet against the inner wall of the main body of the pump can be reduced, and the noise generated in operation of such an air pump can be lowered.

[0007] In a preferred embodiment, the bore diameter of each of the air inlet and the air outlet is about 0.95 mm to 1.5 mm, and most preferably is 1.3 mm.

[0008] The present invention will be apparent in its novelty and features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is an analytic perspective view showing the elements of a preferred embodiment of the present invention;

[0010]FIG. 2 is an analytic perspective view showing the elements on the rear side of FIG. 1;

[0011]FIG. 3 is a sectional view taken from the main body of FIG. 1;

[0012]FIG. 4 is a top view taken from FIG. 3;

[0013]FIG. 5 is a bottom view taken from FIG. 3;

[0014]FIG. 6 is a schematic sectional view showing the assembled elements of the main body of FIG. 1 and the state of air flowing;

[0015]FIG. 7 is a top view taken from FIG. 6;

[0016]FIG. 8 is a bottom view taken from FIG. 6; and

[0017]FIG. 9 is a table of testing data for various bore diameters that the present invention is used with.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] Referring to FIGS. 1-3, taking the main body 10 of the air pump shown as an example, it is provided on one side thereof with an air delivery pipe 11 to connect with an air delivery hose. The main body 10 can be connected on the front and the bottom ends thereof respectively with an elastic cap (not shown) moved reciprocally by a mandrel of a motor.

[0019] In the structure of the main body 10 shown, a first air chamber 14, a second air chamber 15 in communication with the first air chamber 14 and a third air chamber 16 also in communication with the second air chamber 15 are formed along a central hollow post 12 and a middle partition plate 13. The third air chamber 16 is in communication with the laterally disposed air delivery pipe 11. The first air chamber 14 is provided on the periphery thereof with a noise-silencing channel 17 for incoming air. The middle partition plate 13 is provided thereon with an inlet 18 in communication with the first air chamber 14 and the second air chamber 15 as well as an outlet 19 in communication with the second air chamber 15 and the third air chamber 16.

[0020] An incoming air control device 20 and an outgoing air control device 30 are respectively mounted along the inlet 18 and the outlet 19. The incoming air control device 20 and the outgoing air control device 30 are formed from elastic plugs 21, 31 and films 22, 32 made of rubber or the like. The films 22, 32 are positioned in a single direction on the inlet 18 and the outlet 19 respectively in cooperation with the main body 10 of the air pump. The films 22, 32 are respectively extended forwardly to form movable end portions 23, 33 to movably cover the inlet 18 and the outlet 19 in addition to cooperate with the main body 10.

[0021] As shown in FIGS. 6-8, when the air pump is operated to make air flow in the direction as indicated by arrows, the movable end portions 23, 33 of the films 22, 32 being positioned will open in a single direction as is shown (in FIG. 6, the movable end portions 23 of the film 22 below the inlet 18 is slightly raised to open by pushing force of air). Thereby when in operation of the air pump (especially an air pump with two way air incoming and outgoing), the movable end portions 23, 33 of the films 22, 32 will continuously close and open the inlet 18 and the outlet 19.

[0022] Such an air pump makes noise not only because the pumped air passes the air holes, but also because mainly of non stop closing and opening of the air control films on the inlet 18 and the outlet 19 to beat the surface of the middle partition plate 13 of the main body 10 of the air pump. To reduce the beating area of the movable end portions 23, 33 of the films 22, 32 can surely lower noise, however, in an air pump with air output volume of 1200 cc-1600 cc as an example, the diameters of the inlet 18 and the outlet 19 are both set as circa 0.95 mm-1.5 mm of which 1.3 mm is most preferable. To movably cover the air holes, the movable end portions 23, 33 of the films 22, 32 shall be set to have areas in corresponding with the diameters, hence the noise is hard to be lowered.

[0023] The present invention sets the diameters of the inlet 18 and the outlet 19 as circa 0.95 mm-1.5 mm of which 1.3 mm is most preferable. To be coincident with this design of having reduced diameters, the cross-sectional area of the noise-silencing channel 17 is set as one in corresponding with the area of the inlet 18 or the outlet 19. Taking the inlet 18 or the outlet 19 with a diameter of 1.3 mm as an example, the cross-sectional area of the noise-silencing channel 17 is set as (1.3 mm/2)²×π. With this designing, the movable end portions 23, 33 of the films 22, 32 surely can be set as a smaller area in coincident with the reduced diameters.

[0024] In a more preferred embodiment, the elastic plugs 21, 31 of the films 22, 32 for positioning are further provided with forwardly extending portions 24, 34 that are provided with bevel end faces 25, 35. In the preferred embodiment shown, the elastic plugs 21, 31 are mounted in corresponding receiving spaces 101, 102 of the main body 10 of the air pump, and then the films 22, 32 are positioned respectively on the upper and the lower surfaces of the middle partition plate 13, so that the movable end portions 23, 33 of the films 22, 32 are free end pieces covering the inlet 18 and the outlet 19. The forwardly extending portions 24, 34 and the bevel end faces 25, 35 of the present invention can further partly press against the free end pieces or the movable end portions 23, 33, so that the movable end portions 23, 33 of the films 22, 32 are less raised in operation, and the noise generated by beating of the movable end portions 23, 33 can be further lowered.

[0025] The test data for the present invention adopting the diameters within the range of 0.95 mm-1.5 mm for the air holes and the test data for the originally used diameter of 2.0 mm are shown in FIG. 9. Wherein the diameters of the inlet 18 and the outlet 19 are set as 1.3 mm, and when in testing with a distance of 1 meter, the sound volume without loading is 49.4 dB, and the sound volume with a loading is 37.2 dB. When using a diameter of 2.0 mm, the sound volume without loading is 49.4 dB, while the sound volume with a loading is 45 dB, this evidently expresses that the noise in operation is effectively lowered.

[0026] The improved structure of the present invention can thereby effectively lower the noise generated in operation; and surely has the value of industrial utility.

[0027] The embodiment given is only for illustrating the present invention, and not for giving any limitation to the scope of the present invention. It will be apparent to those skilled in this art that various modifications or changes without departing from the spirit of this invention shall also fall within the scope of the appended claims. 

1. A structure of an air pump with low noise, wherein a main body of said air pump is provided on one side thereof with an air delivery pipe to connect with an air delivery hose; on a central hollow post and a middle partition plate in said main body, a first air chamber, a second air chamber in communication with said first air chamber and a third air chamber also in communication with said second air chamber are formed; said third air chamber is in communication with said air delivery pipe laterally disposed; said first air chamber is provided on the periphery thereof with a noise-silencing channel; said middle partition plate is provided thereon with an inlet in communication with said first air chamber and said second air chamber as well as an outlet in communication with said second air chamber and said third air chamber; said inlet and said outlet are respectively mounted with an incoming air control device and an outgoing air control device formed from elastic plugs and films made of rubber or the like, said films are positioned in a single direction on said inlet and said outlet respectively in cooperation with said main body of said air pump; said films are respectively extended forwardly to form movable end portions to movably cover said inlet and said outlet in addition to cooperate with said main body; said structure is characterized by that: the diameters of said inlet and said outlet are reduced to be smaller than that normally used, and the areas of said films are coincidently reduced, the cross-sectional area of said noise-silencing channel is also set in coincidence with said areas of said inlet and said outlet.
 2. The structure of an air pump with low noise as claimed in claim 1, wherein said diameters of said inlet and said outlet are both 0.95 mm-1.5 mm.
 3. The structure of an air pump with low noise as claimed in claim 1, wherein said diameters of said inlet and said outlet are both 1.3 mm.
 4. The structure of an air pump with low noise as claimed in claim 1, wherein said elastic plugs are provided with forwardly extending portions further partly pressing against said movable end portions of said films.
 5. The structure of an air pump with low noise as claimed in claim 4, wherein said forwardly extending portions of said elastic plugs are provided with bevel end faces. 